package com.hmdp.service.impl;

import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.Voucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.SimpleRedisLock;
import com.hmdp.utils.UserHolder;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.util.Collections;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {
    @Resource
    private ISeckillVoucherService iSeckillVoucherService;

    @Resource
    private RedisIdWorker redisIdWorker;

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private RedissonClient redissonClient;

    private IVoucherOrderService proxy;

    private BlockingQueue<VoucherOrder> orderTask = new ArrayBlockingQueue<>(1024 * 1024);
    private ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();

    @PostConstruct
    private void init()
    {
        SECKILL_ORDER_EXECUTOR.submit(new VocherOrderHandler());
    }


    private class VocherOrderHandler implements Runnable
    {

        @Override
        public void run() {
            while(true)
            {
                try {
                    VoucherOrder voucherOrder = orderTask.take();
                    handVoucherOrder(voucherOrder);
                } catch (Exception e) {
                    log.error("处理订单异常",e);
                }
            }
        }
    }

    private void handVoucherOrder(VoucherOrder voucherOrder) {
        //创建锁
        Long userId =  voucherOrder.getUserId();
       // SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
       RLock lock = redissonClient.getLock("lock:order:" + userId);
        //尝试获取锁
        boolean isLock = lock.tryLock();
        if(!isLock)
        {
            //获取锁失败，返回错误信息
            log.error("不能重复下单！");
            return ;
        }
        //获取锁成功
        try {
            proxy.createOrder(voucherOrder);
        } finally {
            lock.unlock();
        }

    }

    private static final DefaultRedisScript<Long> SECKILL_STOCK_SCRIPT;
    static {
        SECKILL_STOCK_SCRIPT = new DefaultRedisScript<>();
        SECKILL_STOCK_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_STOCK_SCRIPT.setResultType(Long.class);
    }
    @Override
    public Result seckillVoucher(Long voucherId) {

        Long userId = UserHolder.getUser().getId();
        //1.执行lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILL_STOCK_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(),
                userId.toString()
        );
        int r = result.intValue();
        if(r!=0)
        {
            return Result.fail(r == 1 ? "库存不足！" : "不能重复下单！");
        }
        //将用户ID，订单ID，优惠券ID添加进阻塞队列
        VoucherOrder voucherOrder = new VoucherOrder();
        //添加订单ID
        long orderId = redisIdWorker.nextId("order");
        voucherOrder.setId(voucherId);
        //添加用户ID
        voucherOrder.setUserId(userId);
        //添加优惠券ID
        voucherOrder.setVoucherId(voucherId);
        //把订单对象添加进阻塞队列
        orderTask.add(voucherOrder);

        //代理对象初始化
        proxy = (IVoucherOrderService) AopContext.currentProxy();

        return Result.ok(orderId);
    }






//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        //1.查询优惠价
//        SeckillVoucher voucher = iSeckillVoucherService.getById(voucherId);
//        //2.判断秒杀是否开始
//        if(voucher.getBeginTime().isAfter(LocalDateTime.now()))
//        {
//            return Result.fail("活动尚未开始！");
//        }
//        //3.判断秒杀是否结束
//        if(LocalDateTime.now().isAfter(voucher.getEndTime()))
//        {
//            return Result.fail("活动已结束！");
//        }
//        //4.查询优惠券库存
//        if(voucher.getStock() < 1)
//        {
//            return Result.fail("库存不足！");
//        }
//
//        //创建锁
//        Long userId =  UserHolder.getUser().getId();
//       // SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
//       RLock lock = redissonClient.getLock("lock:order:" + userId);
//        //尝试获取锁
//        boolean isLock = lock.tryLock();
//        if(!isLock)
//        {
//            //获取锁失败，返回错误信息
//            return Result.fail("不能重复下单！");
//        }
//        //获取锁成功
//        try {
//            IVoucherOrderService proxy = (IVoucherOrderService)AopContext.currentProxy();
//            return proxy.createOrder(voucherId);
//        } finally {
//            lock.unlock();
//        }
//
//    }

    @Transactional
    public void createOrder(VoucherOrder voucherOrder)
    {
        //5.一人一单
        Long userId = voucherOrder.getUserId();
        Long voucherId = voucherOrder.getVoucherId();
        int count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();
        if(count > 0)
        {
            log.error("不能重复下单！");
            return;
        }

        //6.库存减少
        boolean isSuccess = iSeckillVoucherService.update().setSql("stock = stock - 1")
                .eq("voucher_id", voucherId)
                .gt("stock", 0).update();
        if(!isSuccess)
        {
            log.error("库存不足!");
            return;
        }
        save(voucherOrder);

    }

}
